This invention relates to a device for lowering a load along a line, comprising a holder with at least one retarding element acting on the line and activated by the weight of the load.
Such a device, particularly usable as an escape device for persons is known in itself from the published Dutch Patent Application No. 76,11229. In this known device the retarding element consists of a hallow spiral through which the cable goes; the retardation is brought about by friction between the cable and the inner surface of the spiral.
This known device has a number of drawbacks. Although in practice the complete device will undoubtedly be enclosed in a kind of bag the very real danger exists that the cable will be contaminated by dirt or grease so that the friction between cable and spiral decreases, resulting in very dangerous situations. Also when the cable is wound up compactly the whole takes a lot of space and is thus not suited to be taken along on travels. In this known device it is not possible to determine beforehand the friction between the spiral and the cable accurately so that in practice, to ensure that light persons and children can use the escape device safely the structure will be such that there is a low friction so that heavy persons must brake to lower the speed by gripping the cable with one hand; then, too, the lowering speed can easily become much too high. Unconscious persons cannot be brought into safety with this known device. When there is a twist or knot in the cable--which can easily happen--the device is useless.